Farm Progress

It's unclear if the weather pattern of the last few years will repeat in 2018.

Walt Davis 1, Editor

April 4, 2018

3 Min Read
BUSY BOOTH: If there is anything that drives interest in the weather, it’s one of the longest droughts on record. That interest is what drew big numbers of visitors to the National Weather Service during this year’s 3i Show.

Forecasting the weather is pretty reliable three to five days out. It’s even more reliable 24 hours out.

But going the other direction — the further out you try to forecast, the more imprecise the forecast is likely to be.

"There get to be too many variables," said Jeff Hutton, warning coordination meteorologist with the National Weather Service in Dodge City, Kan.

Nonetheless, Hutton attempted to give some guidance on what might be in store for Kansas as the La Niña weakens to a near-normal ENSO condition during a presentation at the annual 3i Show in late March.

Hutton understands the concern of his audience as the second-driest winter on record was coming to an end. Many growers were feeling some relief after about 2 inches of rain and 5 inches of snow in Dodge City in mid-March — moisture that bought some time for the struggling hard red winter wheat crop. It was the first measurable rain since early October.

Hutton said there is no way to know if the weather pattern of the past two years — dry winter and early spring with rains starting in March or April and continuing through a relatively wet summer — will repeat this year, but so far it is setting up that way.

He said that the El Niño Southern Oscillation, which affects the temperature of the waters of the equatorial Pacific off the coast of South America, is only one of several oceanic-atmospheric events that can influence the weather across North America, but it is one of the best known.

The warming of the waters — an El Niño — causes a change of wind currents and, depending on how strong it is, can change the position of the jet stream, which in turn determines the general path of storms moving off the Pacific Coast across the U.S. That event tends to make winter across the southern Plains cool and wet.

The cooling of the waters — a La Niña — also causes a change of wind currents, which pushes the jet stream northward. That blocks cold Arctic air from pushing southward, but also steers storms northward. That leads to warmer and drier weather during the winter months. Both phenomena tend to affect winter weather more than summer weather.

Hutton said that the North Atlantic Multidecadal Oscillation also has an impact on weather across the U.S., since it helps guide the track of storms up the east coast of the U.S. The Pacific Decadal Oscillation is an oceanic event that has a steering effect on west coast storm systems. Two other events that have an impact are the Arctic and Madden-Julian Oscillations.

Hutton said all of the oscillation events can have weather impacts, but just what controls their cyclical patterns is the subject of research.

"The reality is that we just don’t know enough about the origins and impacts of these oceanic/atmospheric relationships to really understand them," Hutton said.

For the 90-day long-range forecast running from April through June, the National Climate Prediction Center shows a likelihood of below-normal precipitation and an equal chance of above- or below-normal temperatures.

"The bottom line is there is not a lot of certainty in looking as far out as June," Hutton said. "We have computer models that put in data from as many data points as we can identify, but it isn’t all that unusual to have something change that throws the model results off target."

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